сб, 27 мая 2023 г., 16:45 Andrew Randrianasulu <randrianas...@gmail.com>:
> Slightly more from my n-th research into colorspaces. > https://video.stackexchange.com/questions/21483/apply-custom-lut-via-ffmpeg this talks about using camera-specific .cube file via ffmpeg. ===== <https://video.stackexchange.com/posts/21653/timeline> You may want to use FFMPEG's lut3d <https://ffmpeg.org/ffmpeg-filters.html#lut3d-1> filter. It requires you to provide a look-up table (a *.cube file). For example, if you have an ARRI camera you can generate these files using ARRI Color Tool <http://www.arri.com/camera/amira/downloads/> or simply download a package with them from the linked page. Once you have the files, use FFMPEG like this: ffmpeg -i "Input.mov" -vf lut3d="ARRIP3D65PQ108-33.cube" -s 1920x1080 -c:v dnxhd -pix_fmt yuv422p -b:v 120M DNxHD_for_Editing.mxf ===== so, if you have those LOG videos with corresponding LUT files you can try this in both ffmpeg command line and opts input file .... https://trac.ffmpeg.org/ticket/2847 this ticket says at very end lut3d uses 32-bit floating point internally, so I guess for it to work (more or less as intended) you need rgba-float project type .... Also, comments warns about "interp" parameter, default might be different from DaVinchi > > https://www.slashcam.com/news/single/Adobe-After-Effects-gets-ACES-workflow-via-OpenCol-17721.html > > Apparently AE (After Effects) got ACES via OCIO just recently: > > > ==== quote == > The traditional Adobe colour management engine (which uses ICC profiles) > has to be switched to OpenColorIO in a project menu for this. > > > > Afterwards, working, composition, display and export colour spaces can be > assigned. > > A plug-in effect "OCIO Color Space Transform" has also been thought of. > This is a colour space conversion effect implemented with the OpenColorIO > engine that can be used anywhere in the composition. This can work with CDL > or LUT files. Complex 3D LUT interpolations are optionally performed > tetrahedral, but this requires a supported(end) GPU. > > ==== > > not sure how "working" vs "composition" differs .... > > Long 13 part series on color management in AE again > > > https://www.provideocoalition.com/color-management-part-13-opencolorio-and-after-effects/ > > === quote === > > As I said above, using OpenColorIO is a conscious decision to do color > management manually, instead of using the built-in color management > system. And this means you need to have a solid understanding of what > you’re trying to do, and why. OpenColorIO was created for use on large > scale Hollywood productions, and the ACES workflows that it’s used with are > designed to future-proof commercial content. > > ==== > https://www.provideocoalition.com/color-management-part-9-workflow-theory/ > > == quote === > > As explained in the video above, the point of a color managed workflow is > that we assign our project a colorspace, and any assets which have a > different colorspace are converted to match the project. But if every > component in our workflow (assets, project, monitor and output) are the > same, then no conversion will be needed. > === > > > c++ example looks simple, but I have no idea if it works transparently > enough to try ... > > > https://opencolorio.readthedocs.io/en/latest/guides/developing/developing.html > > === > *Convert your image, using the Processor.* Once you have a CPU or GPU > processor, you can apply the color transformation using the “apply” > function. In C++ > <https://opencolorio.readthedocs.io/en/latest/guides/developing/usage_examples.html#usage-applybasic-cpp>, > you may apply the processing in-place, by first wrapping your image in an > ImageDesc class. This approach is intended to be used in high performance > applications, and can be used on multiple threads (per scanline, per tile, > etc). > > === > > so, ICC vs OCIO actually a thing ... o.o > > Currently in cingg you have colorspaces plugin and ffmpeg's LUT plugin, > but no support for color-managed display or embedding icc profile in media > .... > > so, *may be* you can add colorspace plugins for equating different media > files manually, and then use external tools (olive-editor?) for > viewing/embedding profiles .... > > > > пт, 26 мая 2023 г., 20:56 Phyllis Smith via Cin < > cin@lists.cinelerra-gg.org>: > >> Updated GIT manual with Andrea's additional screen shot. This manual >> section as previously written by Andrea is a very helpful explanation. It >> is too bad that CinGG does not have better color management and most likely >> never will. ...Phyllis >> >> On Fri, May 26, 2023 at 10:31 AM Andrea paz via Cin < >> cin@lists.cinelerra-gg.org> wrote: >> >>> I added an image as you requested. thanks for the hint. >>> > I guess my 'work' would benefit from RGB-Float, and only at the output >>> > clamp to 8bit. >>> In theory, yes. But in practice many of CinGG's internal processes >>> (e.g., effects) do their own conversions. The result may be >>> unpredictable. Everyone has to look for a satisfactory worflow.... >>> -- >>> Cin mailing list >>> Cin@lists.cinelerra-gg.org >>> https://lists.cinelerra-gg.org/mailman/listinfo/cin >>> >> -- >> Cin mailing list >> Cin@lists.cinelerra-gg.org >> https://lists.cinelerra-gg.org/mailman/listinfo/cin >> >
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